Xenolithic structures are considered to be natural defects in the
igneous rocks that highly affect their physicochemical and mechanical
properties. They are foreign rock fragments trapped in the magma
or lava during the cooling process. They are totally unrelated to the
igneous rocks, as they compose from different types of rock pieces
that enclosed in the monumental granites during their emplacement.
This paper aims to study and characterize the xenolith fragment
trapped in the studied granitic obelisk. The analytical study was
carried out using different techniques such as polarizing microscope,
x-ray diffraction, scanning electron microscope, EDS elemental
analysis and BET surface area. The results clarified that the studied
xenolith fragment is classified as biotite schist xenolith. In addition, it
was observed that the xenolith fragment not only affects the
aesthetic appearance of the studied granitic obelisk but also it
represents a serious weakness point in its structure.